Riffle



Patented Oct. 15, 1929 UNITED STATES PATENT OFFICE RIFFLE v.Application led May 19,

An object of this invention is to provide an improved riiiie for use in the separation of value-bearing ores.V c

A further object of the invention is to provide an improved riiiie for use in combination with an hydrauliceflow method of ore separation.

A further object of the invention is to provide an improved riiiie that will thoroughly agitate the mixture passed thereover, whereby 'a more complete recovery of the values of the ores treated thereon will result. f

A further object of the invention is to bev found in the provision of an improved riflie adapted for continuous operation wher-ein provision is made for discharge of the ore values separate from the sludge.

'A further-object of the invention is to be found in the construction and arrangement of rifie bars, whereby a thorough agitation of the sludge is had and the ore values separated from and retained against the passage of the sludge.

A further object of the invention is tobe found in the provision of an improved riflie that may be used as a single unit or multiplied into a. series of similar units, that is simple and inexpensive of manufacture and durable and efficient in operation.

My invention consists 'in the construction, `arrangement and combination of elements hereinafter set forth, pointed out in my vclaims and illustrated by the accompanying drawing, in which- Figure 1 isa plan view of a sluice equipped with one unit of my improved riffle. Figure 2 is a side elevation of the construction shown in Figure 1. Figure 3 is a longitudinal section on the indicated line 3-3 of Figure 1. 40 Figure l is a cross section on an enlarged scale on -the indicated line 4-4 of Figure 1.

Figure 5 is a fragmentary det-ail section, on

an enlarged scale showing the action of the riflie bars, the direction of flow in the sluice being as indicated by thevarrows. Figure 6 is a fragmentary detail section, on an enlarged scale, illustrating a preferred method of securing the riffle bars through the use of welded fillets. Y

The hydraulic-flow process of ore separa- 1928. VSerial No. 279,004.

tionis well known in its various steps and consists, generally, in running ground or pulverized ore through sluices and over riffles in company with water, the mineral values in the ore, being heavier than the dirt and rock, settle to the bottom of the sluices and are caught in amalgamating basins while the lighter material is carried away by the water. Various modifications of detail are used in carrying out the above process and various combinations of sluices and riiiies may be employed, but the foregoing is sufficient for an understanding of the features embodied in my improved rifle.

In the construction of my improvement, as shown, any suitable sluice may be employed, of any desired width and depth, such a sluice being conventionally illustrated as comprising a bottom 10 and side walls 11 and 12 rising from the margins of said bottom. It is to be understood, of course, that the sluice is to be installed with its bottom'l() in an inclined po rsition longitudinally, so that water will iiow freely therethrough. The riflie comprises a plate 13, of any desired length and of a width preferably greater than that of the sluice in which it is to be mounted, the excess width of the plate 13 being` bent at right angles to the plate to form a channel adapted to fit closely within the sluice and prevent escape of the minute particles of the ore values. The plate 13 may be of a width exactly equal to that of the sluice and side membersl may be secured thereto in place'of the bent-up portions above described, the exact construction being relatively unimportant so long as a channel is provided and the material may be any suitable metal, preferably highly resistant to rust and corrosion. The upstream end of the plate 13 is secured to or overlain by the end of the preceding sluice unit and bars 14, of any desired shape in cross section, are secured to said plate throughout their lengths so that no passage is possible between the bars and plate 13, said bars extending at an angle transversely and longitudinally of said plate, in a downstream direction, and being secured at their outer ends to the channel wall, their inner ends terminating in the midstream portion of the channel in such manner that the first upstream bar extends most nearly across said channel and each successive bar a less distance. Any desired number of the bars 14 may be employed, four being illustrated, and the function of said bars is to agitate the mixture et water and ore and divert the flow thereof diagonally across the channel. Rifle bars 15, round in cross section and of less exter-t above the plate 13 than the bars 14, are secured in spaced relation to the plate 13 in a manner similar to the bars la, said bars 15 extending at an angle transversely and longitudinally of the plate 13 in a downstream direction from the channel wall opposite to that to which the bars 111 are secured. All oft the bars 15 are secured at their outer ends to the channel wall and the irst few of said bars have the termination oi their lengths in staggered relation with the ends of the bars 1d, the remaining bars 15 extending entirely across the plate 13, through a slot in the wall .12 of the sluice and across an extension 15 oi the plate 13 without the sluice. ldarallel riitile bars 1'? are spaced apart transversely et the plate 13 below the downstream end of the slot in the wall oi the sluice and are secured to said plate throughout their lengths and to the channel walls at their ends, the plate 13 having a transverse ridge or step 18 spaced in a downstream direction from said bars 17 and the basin thus formed between said bars 17 and step 18 may contain amalgam to the end that any of the values remaining inthe sludge afte it has passed over the riille bars 15 anc 17 may be caught and retained by the amalgam in said basin.

The operation of the improvement is as follows; the mixture oi water and ore enters the upstream end of the sluice containing the rif'le and strikes against the bars 14, thereby being thoroughly agitated and tumbled about, the current being` diverted diagonally across the sluice against and across the bars 15. T he bars 15, being smaller than the bars 14, do not agitato vthe mixture to a great degreev nor do they divert the current to so great an extent as it iiows across them, but being round, each bar 15 establishes and maintains an eddy current along its upstream side, as is clearly shown in Figure 5, and the heavier particles of the ore, carrying the values, are caught in these eddy currents and carried slowly along one or another ot the bars 15 ont of the sluice and across the plate extension 16 while the sludge remains in the sluice way to be directed as desired; values not caught by the bars 15 being checked by the bars 17 or caught in the amalgam in the basin between said latter bars and the step 18.

1t is or" course obvious that any number of my improved riil'les may be used in a single sluice, or that the values delivered by the bars 15 and extension 16 may be directed into a series of sluices Containing rililes and that ene rillie and its constituent parts may be of any size to meet the needs of a given situation, the illustration and foregoing description being in no sense limitative apart from the scope of the appended claims.

1 claim as my invention- 1. The combination with a Ysluice oi a riflie comprising a relatively long channel member, riffle bars secured at one end to side walls of said channel and throughout their lengths to the bottom ot said channel and extending at an angle transversely and longitudinally of said channel in a downstream direction, some of said bars extending in intersectingdirections and terminating in staggered relation, and a settling basin at the downstream end of said channel.

`2. rlhe combination with a sluice of a riflle comprising a relatively long channel memher formed with one interrupted'margin and a lateral extension of its bottom adjacent and registering with the interrupted portion of said margin, spaced agitating bars secured at one end to one wall of said channel and throughout their lengths to the bottom of said channel and extending at an angle transversely and longitudinally of said channel in a downstream direction, riftle bars, round in cross section, secured at one end to the opposite wall of said channel and throughout their lengths tothe bottom of said'channel and extending at an angle transversely and longitudinally thereof in a downstream' direction, some of said riiile bars terminating in staggered relation with said agitating ybars and others of said riiile bars extending entirely across said channel, through the gap in one wall thereof and across the extension of said channel without said sluice, together with a settling basin adjacent the downstream end of said channel.

3. A rillle comprising a plate, upstanding, marginal walls longitudinally of said plate, one ot said walls having a gap opening to a lateral extension of said plate, round rilitle bars secured throughout their lengths to said plate and at one end each to said uninterrupted wall and extendingdiagonally across said plate in a downstream direction, some of said bars extending through said gap and across said extension, agitating bars on the upstream side of said gap, secured to said plate and at one end each to said interrupted wall, said agitating bars extending across said plate substantially perpendicular to said riliie bars and terminating in staggered relation with some of said riiiie bars, Vand a settling basin between transverse spaced riflle bars and a transverse step in said plate adjacent the downstream end thereof.

l. .A rillie comprising a plate, marginal ywalls longitudinally of said plate, one of said walls having a gap opening to a lateral` extension of said plate, agitatmg bars on said plate adjacent the upstream end thereof and extending in aV downstream directionat an an- 

